/** Created by Dayu Wang (dwang@stchas.edu) on 06-07-2019. */

/** Last updated by Dayu Wang (dwang@stchas.edu) on 06-08-2019. */

package data_structures;

import java.util.Arrays;

public class Array_List<T> {
    private Object[] data;
    private int capacity, used;
    private static final int DEFAULT_CAPACITY = 10;
    public Array_List() { data = new Object[capacity = DEFAULT_CAPACITY]; }
    public Array_List(int cap) { data = new Object[capacity = cap]; }
    public Array_List(Array_List<T> other) {
        capacity = other.capacity;
        used = other.used;
        data = Arrays.copyOf(other.data, other.capacity);
    }
    public Array_List(Object[] other) {
        capacity = used = other.length;
        data = Arrays.copyOf(other, other.length);
    }
    @SuppressWarnings("unchecked")
    public T get(int index) {
        if (index < 0 || index >= used) { throw new IndexOutOfBoundsException("Index: " + index); }
        return (T)data[index];
    }
    public void set(int index, T value) {
        if (index < 0 || index >= used) { throw new IndexOutOfBoundsException("Index: " + index); }
        data[index] = value;
    }
    private void reserve() { data = Arrays.copyOf(data, capacity *= 2); }
    public void add(T value) {
        if (capacity == used) { reserve(); }
        data[used++] = value;
    }
    public void insert(int index, T value) {
        if (index < 0 || index > used) { throw new IndexOutOfBoundsException("Index: " + index); }
        if (capacity == used) { reserve(); }
        for (int i = used - 1; i >= index; i--) { data[i + 1] = data[i]; }
        data[index] = value;
        used++;
    }
    @SuppressWarnings("unchecked")
    public T remove(int index) {
        if (index < 0 || index >= used) { throw new IndexOutOfBoundsException("Index: " + index); }
        T value = (T)data[index];
        for (int i = index + 1; i < used; i++) { data[i - 1] = data[i]; }
        used--;
        return value;
    }
    @SuppressWarnings("unchecked")
    public T remove() throws Exception {
        if (used == 0) { throw new Exception("Attempt to remove item from empty array list."); }
        return (T)data[used--];
    }
    public boolean isEmpty() { return used == 0; }
    public int size() { return used; }
    public boolean contains(T item) {
        for (int i = 0; i < used; i++) {
            if (item.equals(data[i])) { return true; }
        }
        return false;
    }
    public int indexOf(T item) {
        for (int i = 0; i < used; i++) {
            if (item.equals(data[i])) { return i; }
        }
        return -1;
    }
    public int lastIndexOf(T item) {
        for (int i = used - 1; i >= 0; i--) {
            if (item.equals(data[i])) { return i; }
        }
        return -1;
    }
    public void trimToSize() { data = Arrays.copyOf(data, capacity = used); }
    public Object[] toArray() { return Arrays.copyOf(data, used); }
    public void clear() { used = 0; }
    @Override
    public String toString() {
        String output = "[";
        for (int i = 0; i < used; i++) {
            output += data[i].toString();
            if (i != used - 1) { output += ", "; }
            else { output += ']'; }
        }
        return output;
    }
}